At present, China's cattle artificial insemination technology has become very popular. It has played an important role in the improvement of cattle and cows in China. The coverage of improved varieties has been continuously improved, the physical fitness of beef cattle has increased, and the single output of dairy cows has also been greatly improved, which has promoted the development of China's national economy. However, we must be soberly aware that many infertile workers have such problems in the operation of cattle artificial insemination, which brings great losses to livestock production. Specifically, non-standard cattle artificial insemination methods can cause reproductive tract diseases, and also spread reproductive tract diseases, reduce conception rate, cause accidents of humans and animals, increase fetal spacing, reduce milk production of dairy cows, and affect the economic benefits of dairy farms. .
The following analysis shows some irregular operations that are prone to occur during the operation of artificial insemination technology. The following analysis is for reference only.
First, correctly grasp the cow's estrus symptoms and ovulation time
At present, most breeders use the rectum to grasp the technique of insemination. Correctly mastering the cow's estrus symptoms and ovulation time is the basis for successful fertilization of cow eggs. Most breeders do not have a deep understanding of the symptoms of estrus, and the timing of ovulation of cows is not accurate. Some are even vague concepts.
1. Misunderstanding of estrus symptoms
In our practice, most breeders believe that cows that are climbing are estrus cows, that is, stable cows. However, only these are not enough. It should also be added "the cow's reproductive tract changes, normal mucus, normal development of follicles." That is to say, the correct estrus symptoms should be judged from three aspects: "external performance; color, viscosity, flow of mucus; development of follicles". The correct estrus symptoms are: the cow receives other cattle climbing; the mucus that cools into the hanging line; the follicle that is developing on the ovary. These three aspects are specific to the cow's estrus cycle.
2. The erroneous time misunderstanding
Properly mastering the ovulation time of a cow is a key step in the success of artificial insemination, which means correct judgment of when a cow ovulates. Most breeders consider it to be 6 to 10 hours after the end of the cow's estrus. Generally speaking, this is not true. It should be 4 to 16 hours. Some breeders will miss 4 to 6 hours and 10 to 16 hours of ovulation, which will reduce the conception rate. In order to ensure a high conception rate, the follicular development on the ovary should be examined by rectal examination. In general, follicles develop to 1.5 to 2.0 cm. The tip of the follicle is very thin, very swollen, and has a feeling of breaking. Generally speaking, this time the insemination is 100% sure.
Second, correctly master the order of rectal examination
Experienced breeders have to undergo a rectal examination, but many breeders directly examine the follicles on the ovaries. This is prone to misdiagnosis, and there is no cow that excludes uterine inflammation and pregnancy within two months. Because in these two cases, the cow can still estrus, causing mismatch and wasting semen. It is time consuming and laborious, and sometimes causes unnecessary losses. The correct rectal examination is: the palms slowly extend into the rectum, and the palms are turned over. Starting from the cervix, the cervix, uterus, uterine horn, fallopian tubes, and ovaries are touched one by one. Such an examination sequence can exclude the abnormal physiological condition of the reproductive tract, thereby correctly grasping the normal physiological condition of the reproductive tract of the cow, and making a correct judgment for the cow's pregnancy, estrus and inflammation.
Third, proficient in the correct artificial insemination procedures
The correct artificial insemination procedure not only saves time and effort, but also does not easily cause human and animal damage. Here, only some of the problems that are prone to operation are analyzed and described. First, when opening the liquid nitrogen tank, the tank lid should be inverted to avoid contamination; the semen should not be exposed to any unsterilized objects (before entering the reproductive tract); if the vulva is washed with water, 0.1% must be used again. The potassium permanganate solution is cleaned, the artificial insemination gun
head shall not be exposed to the vulva contaminated with water; the artificial insemination device shall not face the body of the insemination personnel, so as to prevent the insemination gun from directly inserting into the reproductive tract to cause serious injury when the cow is retreating; The hindquarters of the cow are kept to prevent the cow from injuring the insemination personnel; after the insemination is finished, the artificial insemination gun is slowly taken out, and the center of the clitoris or the back of the back is pinched to make it collapse and prevent semen from flowing backward.
Fourth, the misunderstanding of timely insemination
Most breeders determine the time of insemination by observing the cow's estrus. The cows ate in the morning and bred in the afternoon. The cows estrus in the afternoon and they will be bred the next morning. This method has some truth, but it is not accurate enough. Accurate insemination time is a comprehensive judgment of the intrinsic and extrinsic performance of cows:
1. External performance: The estrus cow is transferred to the late stage of estrus, and the cow is quiet and the appetite gradually returns to normal. When other cattle climbed across, the cow's buttocks evaded the vagina and swollen and wrinkled.
2. Mucus: The vaginal mucosa is dark red, the mucus volume is small and the mucus color is cloudy or grayish white.